Electronic Telegram No. 57
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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CBAT@CFA.HARVARD.EDU (science)
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SUPERNOVA 2004C IN NGC 3683
C. C. Dudley and J. Fischer, Naval Research Laboratory,
report the discovery of a new point source (mag K' about 14)
in NGC 3683 observed with the U.S. Naval Observatory 1.55-m telescope
(+ 2.1-micron K' filter + ASTROCAM 1024x1024 ALADDIN InSb imager) on
at Flagstaff on Jan. 12.5 UT. The position of the source is R.A.
= 11h27m29s.72 Decl. = +56o52'48".2 (equinox 2000.0), based on
positions of three 2MASS stars, which is 17" west and 10" north
of the K' nucleus of NGC 3683. The source shows no perceptible drift
over 8 min (seeing about 1") and was not present on 2003 May 18, the
most recent prior observation with ASTROCAM.
T. Matheson, P. Challis, and R. Kirshner, Harvard-Smithsonian Center
for Astrophysics, report that a spectrum (range 370-750 nm) of SN
2004C, obtained by P. Berlind on Jan. 15.51 UT with the F. L. Whipple
Observatory 1.5-m telescope (+ FAST spectrograph), shows it to be a
type-Ic supernova, similar to SN 1990U about three weeks past maximum
(see Matheson et al. 2001, A.J. 121, 1648). The spectrum is highly
reddened and shows a strong, narrow Na I D absorption at the velocity of
the host galaxy with an equivalent width of 0.3 nm. The dust maps of
Schlegel et al. (1998, Ap.J., 500, 525) indicate a low value for
Galactic reddening of E(B-V) = 0.015.
NOTE: These 'Central Bureau Electronic Telegrams' are intended to
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(C) Copyright 2004 CBAT
2004 January 15 (CBET 57) Daniel W. E. Green